Many photographic materials, particularly color negative films, contain so-called DIR (development inhibitor releasing) couplers. In addition to forming dye, DIR couplers release inhibitors that can restrain silver development in the layer in which release occurs as well as in other layers of a multilayer photographic material. DIR couplers can help control gamma or contrast, can enhance sharpness or acutance, can reduce granularity and can provide color correction via interlayer interimage effects. There has been a need for more effective magenta dye-forming DIR couplers. Magenta DIR couplers that provide high interimage color correction are particularly desirable for modem color negative films. The combinations of DIR couplers and pyrazolone magenta dye-forming imaging couplers of this invention possess all of these desirable properties, particularly the ability to provide higher interimage than combinations of the prior art.
The DIR couplers of this invention are known as one of many types of DIR couplers and are shown, for example, in U.S. Pat. No. 4,477,563. Deactivating the inhibitor in the processing bath is the object of this patent. This patent suggests a wide range of image coupler and a wide range of DIR couplers, but does not suggest the particular combination of the invention. U.S. Pat. Nos. 5,250,405 and 5,546,848 teach a broad range of couplers and all known DIR couplers but neither teaches nor recognizes the advantages of the invention. The patent is focused on the prevention of continued coupling through the use of a particular solvent for the couplers. U.S. Pat. Nos. 4,853,319; 5,250,405; 5,256,528; 5,350,667; 5,376,519 and 5,462,848 disclose pyrazolone imaging couplers similar to the imaging couplers in the combinations of the current invention. None of these patents shows the advantageous interimage effect of the combination of the invention. As shown hereafter, other DIR couplers taught and used in working examples in the patents give inferior results in interlayer interimage.
It is a problem to be solved to provide a green light sensitive imaging layer which exhibits satisfactory interlayer interimage without sacrificing other properties such as stability, or undue loss of green sensitive layer gamma.